1. Field of the Invention
The present invention relates to an information processing apparatus, an imaging apparatus, an information processing method, and a computer program. More specifically, the invention relates to an information processing apparatus, an imaging apparatus, an information processing method, and a computer program, which have the configuration that is intended to shorten a starting time as well as to reduce power consumption.
2. Description of the Related Art
In general digital cameras, a predetermined time period (a few seconds) is necessary to power a power source on from a power source off state in which a main switch is off and to establish a state to allow actual shooting. This is because a system startup process is necessary such as a process in which information necessary for an imaging process is decompressed over storing means such as an SDRAM as a volatile memory after the main switch is turned on.
Such a state is called as a hot standby state that information necessary for the imaging process is decompressed over the storing means such as an SDRAM to complete a system startup process. After the state is shifted to the hot standby state, an actual imaging process can be conducted.
A reduction in the transition time period from powering the power source to the shootable state is one of problems of the digital camera. For example, JP-A-2000-59675 (Patent Reference 1) disclose a configuration in which in a digital still camera that allows mode settings such as a recording mode and a reproduction mode, the mode is changed to a power saving mode unless otherwise a user makes a manipulation within a mode duration time defined in accordance with each mode, whereas once a mode is set, the mode is continued not to enter the power saving mode within the defined time period set in accordance with each mode, whereby the imaging process can be conducted immediately within the mode duration time.
In addition, for example, JP-A-2005-173620 (Patent Reference 2) discloses a configuration which realizes a reduction in the starting time by maintaining the hot standby state described above. More specifically, Patent Reference 2 discloses a camera configuration having a warm sleep state which continues the hot standby state that information necessary for the imaging process is decompressed over the storing means such as an SDRAM.
According to the configuration described in Patent Reference 2, even though the power source is in an off state, in the warm sleep state, power is continuously supplied to the storing means such as an SDRAM having information necessary for the imaging process stored therein. Accordingly, the hot standby state can be maintained, and shooting can be started immediately when a user intends to start shooting and turns the power source on.
However, in the configurations described in both Patent References, in order to continuously maintain a predetermined mode or the hot standby state, it is necessary to continuously supply power to the storing means (SDRAM) having information necessary for the imaging process therein. Consequently, there is a problem that power consumption becomes great. In both Patent References, the configuration is shown in which a predetermined timeout time period is provided to release a predetermined mode or the hot standby state. However, when a predetermined mode or the hot standby state is released, in the shooting operation after that, the time period from the power source on to the shootable state is the same as the time period in the camera before, causing a problem that a reduction in the starting time can not be exerted.